@article{SM_1976_30_4_a2,
     author = {E. P. Dolzhenko and E. A. Sevast'yanov},
     title = {Approximations of functions in the {Hausdorff} metric by piecewise monotonic (in particular, rational) functions},
     journal = {Sbornik. Mathematics},
     pages = {449--477},
     publisher = {mathdoc},
     volume = {30},
     number = {4},
     year = {1976},
     language = {en},
     url = {http://geodesic.mathdoc.fr/item/SM_1976_30_4_a2/}
}